The field of the invention is wireless information devices and more specifically wireless devices for automatically obtaining location based information related to machines when a wireless device is placed within proximity of the machines.
There are many industries where electronic interfaces have been developed to facilitate monitoring or control or both system monitoring and control. For instance, in the industrial automation industry, a manufacturing plant may include several thousand different machines arranged to form a plurality of machine lines that cooperate to produce products. In this case, each machine or a sub-set of machines may be equipped with an interface including a processor, some type of information output device and some type of information input device. The output device is often a display screen for displaying text, graphics, etc., and the input device is typically a keyboard.
Because of the nature of industrial automation, some industrial facilities have adopted policies requiring local or location specific control and associated interfacing. In industrial control, many (e.g., tens or perhaps even hundreds) machines may be positioned along a machine line so that improper performance of, or damage to, one machine affects operation of a large number of related downstream machines. In addition, improper machine operation, given unforeseen circumstances, may result in injury to facility employees proximate the malfunctioning machine or proximate downstream machines. In these cases, if remote control were allowed, an operator may alter operation of one machine believing that some other similar machine is being adjusted with unintended and potentially costly results.
In an effort to avoid unintended results, many automated facilities require operators to be located adjacent or proximate a machine prior to altering machine operation. This proximity requirement is enforced by providing machine monitoring and controlling interfaces proximate associated machines. More specifically, the interfaces are typically placed in positions that enable an interface operator to observe machine operation prior to, during and after adjustment of machine operating characteristics. Here, the interfacing is local despite remote or centralized processing. In this manner, an operator can essentially simultaneously observe operation of a particular machine and the information provided by an interface associated with the particular machine. This “dual viewing” capability facilitates a far more comprehensive understanding of machine conditions and enables the operator to quickly determine if control alterations have desired effects.
Requiring even basic interfaces at each machine or adjacent logically related sub-sets of machines is relatively expensive as each interface typically requires a display of some type and at least a set of control buttons or a keyboard of some type. To minimize costs many control systems are designed to provide multiplexed control where one interface may be provided for several proximate machines. For instance, one interface may be provided for ten proximate machines.
Multi-machine interfaces represent a tradeoff between cost and functionality. To this end, as indicated above, unfortunately, the “dual viewing” (i.e., simultaneous view of a machine and an associated interface) capability afforded by providing interfaces as close as possible to associated machines is hampered when the number of interfaces is less than the number of machines within a facility. Thus, in the case above, where a single interface is provided for ten separate but proximate machines, the interface may not be located in an optimal position for observing operation of a sub-set of the ten machines while simultaneously viewing the interface.
In addition, where a single interface is provided for more than one machine, the interface has to be relatively more complex than an interface provided for a single machine. To this end, to avoid confusion and unintended changes to machine operation, it is generally accepted that an interface should only display information corresponding to a single machine or a related subset of machines at any given time. For example, where a single interface is provided for accessing information corresponding to and controlling ten logically related machines, if the interface were programmed to provide information and controls for two or more of the machines at one time, an interface operator may examine data corresponding to one of the ten machines believing that the examined data corresponds to another of the ten machines or worse, the operator may adjust control of one of the ten machines believing that the operator is controlling another of the ten machines.
To avoid this type of confusion and related control errors, multi-machine interfaces are typically programmed so that information and control tools corresponding to only a single one of the machines associated with an interface are provided at any time. Thus, multi-machine interfaces generally require some type of machine selection process and corresponding tools that allow a user to select which of several machines the user wishes to interrogate and/or control and hence are more complex than single machine interfaces that can automatically provide information to an operator.
Furthermore, in the case of multi-machine interfaces there is always the possibility that an operator may inadvertently select one machine believing that the operator has selected another machine for monitoring or control. Here, as above, the possibility for an unintended and costly result is great.
As in most businesses, in an automated facility, there are many different types of employees and machine access and control requirements for the employee types are very different. For instance, a janitor likely has no need to access machine information or control machine operation, a maintenance engineer will require access to certain machine information and control capabilities and a process engineer may require access to a completely different set of machine information and control capabilities. Systems have existed for a long time that can restrict information access and control to specific authorized personnel (e.g., password protection, biometric comparison, etc.). Unfortunately, these systems generally require relatively complex and expensive interface devices (e.g., a complete keyboard or some type of biometric scanner). As indicated above, in automation, most interfaces are minimized to reduce costs and hence the added security that comes with restricting access and control to those having a need to access and control are often foregone.
One solution to the above problems that has been used in the automation industry is to provide hand held devices (HHDs) to machine operators having a need to monitor and/or control facility machines. (Unless indicated otherwise all portable information devices hereinafter will be referred to as HHDs, including PDAs, laptops, etc.). Here, an HHD, as its label implies, is a relatively small and portable device that can be carried around a facility by a machine operator. The HHD is typically provided with a small display screen, a set of buttons or a full keyboard to enable information interchange, a processor, a memory and a communication cable having a distal end configured to be received by a machine port. Each facility machine is provided with a machine port for receiving the HHD cable. To link to a local machine processor, the HHD cable is plugged into the machine port and establishes a one-to-one match where there is no ambiguity.
Here, information access and control can be restricted by restricting access to the HHDs. Thus, for instance, when a maintenance engineer enters a facility to perform maintenance duties, the engineer may check out an HHD from a central HHD location for use in the facility. After the maintenance engineer has completed his duties, the engineer may be required to check the HHD back into the central HHD location. To restrict access and control differently for different personnel there may be classes of HHDs where each class allows a user a unique set of access and control privileges (i.e., a maintenance HHD may have a first set of capabilities while a process control HHD may have a second set of capabilities). Unfortunately the HHD solution described above also has several shortcomings. First, the manual process of linking an HHD to a machine processor is time consuming, burdensome and costly. Again, while one or a small number of linking processes may not seem burdensome, where the process has to be repeated several hundred times during an operator's shift, the combined linking tasks become excessive. In addition, there may be a safety risk in this case and the connection plug may not always be accessible.
Second, where several hundred links may have to be made during a given day, the wear and tear on machine communication ports and HHD cable can be excessive and require either routine replacement or an extremely robust and expensive mechanical linking system.
Third, despite support for some customization regarding the types of information and control provided to a facility employee by way of configuring HHDs as a function of the type of employee that will use the HHD, there is no easy way to allow an employee to customize the appearance of information and control tools provided by the HHD. For instance, one maintenance engineer may want a first set of information presented in a first format while another maintenance engineer may want the same first set of information presented in a second format completely different than the first format.
Fourth, any system that requires an HHD to be tethered to a machine in order to obtain information related to the machine or to control the machine restricts operator movement and may not allow an operator to move into particularly advantageous positions to observe machine operations. Also, in this regard, a mechanical tether is cumbersome to manipulate and therefore is bothersome.
Industries outside industrial automation have faced problems similar to those faced in industrial automation and have devised some solutions that are suitable to the respective industries. For instance, in the medical industry, it has been recognized that the ability to obtain information about a patient automatically upon entering the patients room is advantageous. In a medical facility, a process that requires a physician to manipulate a patient's arm to identify a patient ID on a wristband or the like and then enter the patient ID into an information device to obtain the patient's medical history is burdensome. The process may disturb a sleeping patient, requires that the physician come in close proximity to the patient, is subject to human error and is time consuming. The process is particularly burdensome in emergency situations where time may be of the essence.
European patent application No. 0,992,921 (hereinafter “the '921 reference”) entitled “Computer Access Dependent On Location of Access Terminal” which was filed on Sep. 21, 1999 teaches a facility system wherein a separate wireless access point is positioned within each facility room for communicating with physician specific wireless HHDs located within the room. The '921 reference teaches that a physician identifier is stored in the HHD and, when an HHD is sensed within a room, the access point automatically obtains the physician identifier from the HHD, determines a degree of access (i.e., authorization) associated with the physician identifier, accesses information associated with the room (i.e., information associated with a patient within the room) and then transmits a sub-set of the patient information consistent with the physician's degree of access to the HHD for display.
The '921 solution works well in a facility that can easily be divided into cells separated by walls (i.e., patient rooms) and where there is only one set of information (i.e., information related to a single patient) associated with a particular cell. However, if a plurality of patients are located within a single room the '921 reference system cannot determine for which of the plurality of patients a physician seeks information. It is unclear how the '921 reference would resolve the quandary regarding which patient information to provide to a physician when more than one patient resides in a room. The '921 reference presents a problem where a physician may end up reviewing information corresponding to one patient while examining a different patient in the same room—clearly an unacceptable situation. In the context of an automated facility the '921 reference could not be used to select information corresponding to one machine out of a plurality of machines in a room for delivery to an HHD. In addition, in this regard, in many automated environments, several hundred or even thousand monitorable/controllable machines may be located in a single room or space and many of the machines may have similar descriptions so that, for instance, identifying one drill press from within a room including 100 drill presses would be a potentially confusing task.
In addition, the '921 reference fails to teach or suggest any type of location specific equipment control. Failure to discuss equipment control is not surprising given the relatively course location resolution contemplated by the '921 reference.
Moreover, the '921 reference system and other systems of the same ilk require a relatively large number of access points to provide even the relatively coarse location resolution capabilities contemplated. System cost increases along with component count and therefore systems like the '921 reference system are relatively expensive.
In the office automation industry, U.S. Pat. No. 6,359,711 (hereinafter “the '771 patent”) which issued on Mar. 19, 2002 and is entitled “System and Method for Supporting A Worker In A Distributed Work Environment” teaches a system where, like the '921 reference, a single access point is located within each room in a facility. The '771 patent teaches that HHDs (i.e., laptop computers) used by specific users are provided with user identifiers. A system database correlates user identifiers with information related to applications that the specific users subscribe to or have authorization to use. In addition, the database also includes information related to office equipment located throughout a facility where the equipment is associated with specific applications. For instance, a word processor application may require access to a printer, a window treatment control application may require access to motorized blinds and an HVAC application may require access to a thermostat control.
The '771 patent teaches that a separate access point is provided in each room. When an HHD is brought into a room, the access point in the room senses the HHD, obtains the user identifier therefrom, accesses the database to identify applications associated with the user identifier, identifies which office equipment types the identified applications must access, locates the single instance of each identified office equipment type that is closest to the access point and then creates a control link between the laptop and the identified equipment instances.
While suitable for an office environment, the '771 patent control scheme is not suitable for an industrial automation environment for several reasons. First, the '771 patent system, like the '921 reference system, relies on clearly delineated and identifiable facility cells (i.e., rooms) and a single access point in each cell. Like the '921 reference, the '921 patent system cannot determine relative proximity between the HHD and a plurality of machines located within a single room. For instance, where an HVAC control, a printer and a laptop are located in the same room, the '771 patent cannot determine if the laptop is closest to the HVAC control or the printer.
Second, the '771 patent system teaches linking a laptop to the closest instance of each required equipment type independent of whether or not the instance is proximate the HHD. For instance, in the case of a word processor application requiring a printer, the '771 patent system locates a closest printer to an access point and enables control of the located printer irrespective of the distance between the printer and the laptop (i.e., the access point). Here, the printer may be five rooms away from the HHD and hence from the person operating the printer. This type of “blind” control is acceptable in the case of a printer application where the end result of an imperfect printing process has a minimal associated cost. However, in the case of automated control of machinery, as indicated above, such blind control often cannot be tolerated.
Third, a system like the '771 patent system would cause confusion in an industrial control environment. To this end, while a particular user may have clearance to observe machine information corresponding to several different machine types and to control various machine types using various applications, simultaneously and automatically presenting information or controls corresponding to two or more machine types at a time would be confusing where only a single machine type can be controlled at any one time.
World patent application No. WO 00/50919, (hereinafter “the '919 reference”) Which is titled “Method and Computer Readable Medium for Locating and Tracking a User in a Wireless Network Using a Table of Digital Data” teaches one system that can be used to relatively accurately determine location within a specific space or within a room. To this end, the '919 reference teaches that a plurality of base stations or access points can be installed at locations within a facility. The access points each transmit signals of known strength to mobile HHDs within the facility. The strengths of the signals decrease as a function of distance traveled by a signal. The HHDs each receive the transmitted signals and, based on signal strengths of several of the received signals, determine the location of the HHDs within the facility.
While the '919 reference system advantageously reduces the cost of a location tracking system by reducing the number of required access points within a facility, it is believed that the location resolution and reliability attainable via the '919 reference system will not be sufficient for industrial automation purposes where several different machines may be very close to each other on a facility floor.
World patent application No. WO 02/054813 (hereinafter “the '813 reference”) titled “Location Estimation in Wireless Telecommunication Networks” teaches a location system similar to the system described in the '919 reference that relies on signal strength to determine location of a portable device within a facility. The '813 patent, however, applies a statistical model to the received signals to, supposedly, yield a far more accurate device location. Neither of the '919 reference nor the '813 reference contemplates providing machine information or control capabilities based on HHD location.
Thus, it would be advantageous to have a system that could automatically provide machine specific information to an HHD when the HHD is located proximate the machine where the machine is one of a plurality of different machines located in a single room. Automatic information customization for HHD operators would also be advantageous.